1. Field of the Invention
This invention relates to a method of and apparatus for dyeing or otherwise treating fabrics in the form of cloth, tapes, yarns and other elongate materials.
2. Prior Art
An apparatus known in the art of fabric dyeing typically comprises a cylindrical vessel in which hot dye liquor is circulated, and a cylindrical beam rotatably mounted on a drive shaft journalled in the vessel and having wound thereon a fabric material to be dyed. Since the beam was only rotatable with the shaft and held otherwise immovable, the material wound on the beam was susceptible to swelling or shrinking on contact with heated dye medium and consequently pressed under increased tension against the periphery of the beam. This would lead to insufficient dye penetration in the areas of the fabric material which were held in close contact with the beam, and as a result, it was difficult to dye the material homogeneously throughout its entire dimensions. This problem would become aggravated in the case of dyeing a chain of slide fastener stringers where the chain was subjected to excessive tension particularly in the region of the coupling head portions in the rows of coupling elements secured to the tape edges, resulting in deformed or otherwise inoperative coupling elements.